Molecular, Biochemical, and Cellular Basis of Genomic Disease

Flashcards based on the molecular, biochemical, and cellular concepts related to genomic diseases, including definitions and key terms.

Lysosome

An organelle containing enzymes that break down waste materials and cellular debris.

Novel Property Mutations

Mutations that confer a new property to a protein without altering its original function due to a change in amino acid residue.

Allelic Heterogeneity

Different mutations in the same gene lead to the same phenotype.

Locus Heterogeneity

Mutations at different genetic loci produce the same phenotype.

Gain-of-Function Mutations

Mutations that enhance the normal function of a protein or lead to a new function.

Loss-of-Function Mutations

Mutations that result in reduced or abolished protein activity.

Hyperphenylalaninemia

A metabolic disorder characterized by elevated levels of phenylalanine in the blood.

Hexosaminidase A

An enzyme involved in the metabolism of gangliosides; deficiencies lead to Tay-Sachs disease.

Pleiotropy

A phenomenon where a single gene mutation results in multiple phenotypic effects.

Genetic Heterogeneity

The occurrence of the same phenotype resulting from mutations in different genes.

Mitochondria

Organelles responsible for producing energy in eukaryotic cells through oxidative phosphorylation.

Autosomal Recessive

Inheritance pattern where two copies of an abnormal gene must be present for the disease to develop.

Biochemical genetics

Study the phenotypes at the levels of proteins, biochemistry and metabolism

Heterochronic mutations

Mutations that alter the regulatory regions of a gene to cause inappropriate expression at an abnormal time

Ectopic mutations

Mutations that alter the regulatory regions of a gene to cause inappropriate expression at an abnormal place

Housekeeping proteins

Class of proteins that is present in virtually all cells, fundamental for the maintenance of cell structure and function, account for 90% of mRNAs expressed in humans

Tissue-specific speciality proteins

Expressed in only 1 or a limited number of cell types, have unique functions, account for 10% of mRNAs expressed in humans. May cause disease restricted to those tissues or disease in a secondary site where the protein is NOT expressed.

Modifier gene

A gene that modifies the effect produced by another gene

Enzymes

Biological catalysts that mediate the efficacy of converting a substrate to a product

Enzymopathy

A genetic disorder caused by the dysfunction of a specific enzyme, leading to metabolic abnormalities.

Phenylketonuria (PKU)

An autosomal recessive disorder resulting from mutations in PAH. Elevated phe levels in body fluids damage the developing CNS in early childhood. and interferes with the function of the mature brain, resulting in mental retardation.

Ganglioside

A lipid molecule composed of a glycosphingolipid with one or more sialic acids linked on a sugar chain

Gangliosidosis

Lipid storage disorder caused by the accumulation of lipids, gangliosides

Tay-Sachs disease

Heterogenous lysosomal storage disorder characterized by the deficiency of the enzyme hexosaminidase A (Hex-A). This leads to the accumulation of GM2 gangliosides, primarily affecting the nervous system and resulting in severe neurological decline.

GM2 gangliosidoses

A group of genetic disorders that result from the inability to degrade the sphingolipid of gangliosides